Benchmark: Date.now() vs new Date().getTime(qu)

Script Preparation code:

var timestamp = null;

Tests:

Date.now()
timestamp = Date.now();
new Date().getTime();
timestamp = new Date();

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Date.now()
new Date().getTime();

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 3 years ago)

User agent: Mozilla/5.0 (Windows NT 6.3; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/91.0.4472.124 Safari/537.36

Browser/OS: Chrome 91 on Windows 8.1

View result in a separate tab

Test name	Executions per second
Date.now()	687362.0 Ops/sec
new Date().getTime();	615288.9 Ops/sec

Autogenerated LLM Summary (model llama3.2:3b, generated 2 months ago):

LLMs can make mistakes. Check important info.

Let's break down what's being tested in the provided JSON benchmark.

**What's being tested?**

The benchmark is comparing two approaches to get the current timestamp:

1. `Date.now()`
2. `new Date().getTime()` (or simply `.getTime()`)

These two methods are used to retrieve the number of milliseconds since the Unix Epoch (January 1, 1970, 00:00:00 UTC).

**Options compared**

The two options being compared are:

* `Date.now()`: This method is a built-in function in JavaScript that returns the number of milliseconds since the Unix Epoch. It's often used when you need to get a precise timestamp.
* `.getTime()`: This method is also part of the `Date` object and returns the number of milliseconds since the Unix Epoch. However, it's not as commonly used as `Date.now()`.

**Pros and Cons**

**`Date.now()`**

Pros:

* More concise and readable
* Less overhead compared to using the `.getTime()` method

Cons:

* May be slower due to the way it's implemented (it involves getting the current timestamp from the system clock)
* Less precise than using `new Date().getTime()` (which can provide more accurate results)

**`.getTime()`**

Pros:

* More precise and accurate, as it gets the result from the system clock directly
* Can be useful if you need extremely high precision

Cons:

* Longer syntax (it requires accessing a nested property on the `Date` object)
* Less readable and less concise compared to `Date.now()`

**Other considerations**

Both methods have their own subtleties. For example, `Date.now()` returns an integer value between 0 and 2^53-1, while `.getTime()` returns a timestamp in milliseconds since January 1, 1970, 00:00:00 UTC.

It's also worth noting that both methods are subject to the limitations of JavaScript's internal clock resolution. In general, this is measured in nanoseconds or even fewer (depending on the system and browser).

**Libraries and special features**

There are no libraries mentioned in the provided code snippet. However, it's common for benchmarks like these to use a library like ` benchmark.js` to handle the actual measurement of execution time.

If you need to test specialized JavaScript features or syntax, other alternatives might include:

* `benchmark.js`
* `perf_hooks`: a built-in Node.js module that provides high-resolution performance counter functionality
* `v8-perf`: a tool for profiling and benchmarking V8 (the JavaScript engine used in Google Chrome)

Keep in mind that the specific library or approach will depend on your use case and requirements.

Related benchmarks:

Date.now() vs new Date().getTime(qu) (version: 0)

Comparing performance of: Date.now() vs new Date().getTime();

Created: 3 years ago by: Guest

Jump to the latest result

Date.now()

new Date().getTime();

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 2 months ago):